render time is way long

Good day folks

im enjoying usingUE4 every second of it but as a new software to me im having challenges. got few questions hope you’ll forgive me.

  1. i know my computer is old but do you think is affecting render time. this scene is rendering for more than 24 Hours is that normal? i paint the grass after building the light in production.

Intel(R) Core™ i7 CPU 920 @ 2.67GHz, 2661 Mhz, 4 Core(s), 8 Logical Processor(s)
Installed Physical Memory (RAM) 16.0 GB DDR3
GForce GTX 970

  1. how can i illuminate my interior with out affecting exterior lighting?
  2. im not happy with my reflections, please look at the doors they suppose to reflect the environment, the pool and chairs not the cubemap
  3. do you thing GPU lightmass can solve the render time? and where can i get get it for UE4 4.21.2

Your CPU is very old, that’s probably the primary reason it takes too long. If you want more light on the inside then you need to put lights on the inside

You should be able bake a scene like within an hour. Especially if it’s mostly a mostly empty exterior scene. Interior render times can really sky rocket after cranking to the quality and bounces.

​​​​​​You can try to use Luoshuang’s GPULightmass, not every feature is supported and there are bugs.

You can use different lighting channels and/or post processing volumes for the interior.

You can try putting reflection capture actors right in front of windows, try box captures if you aren’t happy with the spheres. You can also try planar reflections or generating cubemaps.

A lot goes into optimizing geometry to bake well and quickly.

  1. For now you will need more CPU cores for faster rendering. I don’t feel comfortable with 16GB RAM, 32GB is way more expensive, but you can have larger projects.
  2. You can use rectangular lights pointing to the interior and give them the windows/doors dimensions, this way light is unlikely to mess with exterior lights
  3. For the doors, which is the material setup? Did you place planar reflections with 100% screen percentage?
  4. Did you check the Lightning Academy videos? There is a lot of info there, they can be found starting here

Those also!!

thansk for the reply i will try to get More ram and Good processor. what about My GPU?

The mentioned Luoshuang’s GPULightmass is the only thing currently relying on GPU, everything else is done by CPU. Note that until the end of year, technology are more consolidating on Raytracing technologies to have real-time lights, reflections and shadows with almost baked light quality. It is still a young technology, some features will be already present at UE 4.22 and more at 4.23.

I would suggest to wait a little bit more before any purchases, but right now you are good with your GPU and for the current way of doing things a 8c/16t CPU is way affordable than a 2 years ago and will last for more 5 years to come.

Things that will increase your build time:

World settings:

  • Static Lighting Level Scale < 1.0
  • Num Indirect Lighting Bounces > 3
  • Num Sky Lighting Bounces > 1
  • Indirect Lighting Quality > 1.0

Build Settings: Preview is the fastest and Production is the slowest.
Large light map sizes

I’m absolutely not saying that you should not tweak these settings. You should. But it will increase your build times.

A preview build in default settings should only take a few minutes on your machine for this scene. I am suspecting the grass may cause the delay. Try to set its mobility to movable and untick the cast shadow box. See how it goes. If it is still longer than a few minutes set all the above settings to default and then increase them one by one until the time starts to get very long.

You could use a bit more memory. I have an old i7 3000 series and its running fine. CPU isn’t the most important thing in unreal.

Did you add reflection captures?

I would consider a Ryzen 2 2700X, you can get one (with heatsink and fan) for under $300. Check the Slickdeals website.

A compatible motherboard is $75 or less. I upgraded to this late last year from an i7-6700k, and the extra cores helped. I use GPU lightmass (the thread is in the Rendering forum here), so I bought the Ryzen as a modest upgrade, saving money for RTX video cards later on when they’re supported. Just my suggestion.

Well, for some hope… check this out. I did this with only 2gigs of vram and 12gigs of ram. On a i7. Took about 45 minutes to bake. I used to get over 30hour render times in my learning stage. But soon learned to optimize everything. Here’s the link…